About Me

My mother was murdered by what I call corporate and political homicide i.e. FOR PROFIT! she died from a rare phenotype of CJD i.e. the Heidenhain Variant of Creutzfeldt Jakob Disease i.e. sporadic, simply meaning from unknown route and source. I have simply been trying to validate her death DOD 12/14/97 with the truth. There is a route, and there is a source. There are many here in the USA. WE must make CJD and all human TSE, of all age groups 'reportable' Nationally and Internationally, with a written CJD questionnaire asking real questions pertaining to route and source of this agent. Friendly fire has the potential to play a huge role in the continued transmission of this agent via the medical, dental, and surgical arena. We must not flounder any longer. ...TSS

Sunday, June 29, 2014

Transmissible Spongiform Encephalopathy TSE Prion Disease have now been
discovered in a wide verity of species across North America. typical C-BSE,
atypical L-type BASE BSE, atypical H-type BSE, atypical H-G BSE, of the bovine,
typical and atypical Scrapie strains, in sheep and goats, with atypical Nor-98
Scrapie spreading coast to coast in about 5 years. Chronic Wasting Disease CWD
in cervid is slowly spreading without any stopping it in Canada and the USA and
now has mutated into many different strains. Transmissible Mink Encephalopathy
TME outbreaks. These Transmissible Spongiform Encephalopathy TSE Prion Disease
have been silently mutating and spreading in different species in North America
for decades.

The USDA, FDA, et al have assured us of a robust Triple BSE TSE prion
Firewall, of which we now know without a doubt, that it was nothing but ink on
paper. Since the 1997 mad cow feed ban in the USA, literally tons and tons of
banned mad cow feed has been put out into commerce, never to return, as late as
December of 2013, serious, serious breaches in the FDA mad cow feed ban have
been documented. The 2004 enhanced BSE surveillance program was so flawed, that
one of the top TSE prion Scientist for the CDC, Dr. Paul Brown stated ; Brown,
who is preparing a scientific paper based on the latest two mad cow cases to
estimate the maximum number of infected cows that occurred in the United States,
said he has "absolutely no confidence in USDA tests before one year ago" because
of the agency's reluctance to retest the Texas cow that initially tested
positive. see ; http://www.upi.com/Health_News/2006/03/15/Analysis-What-that-mad-cow-means/UPI-12841142465253/

The BSE surveillance and testing have also been proven to be flawed, and
the GAO and OIG have both raised serious question as to just how flawed it has
been (see GAO and OIG reports). North America has more documented TSE prion
disease, in different documented species (excluding the Zoo BSE animals in the
EU), then any other place on the Globe. This does not include the very
likelihood that TSE prion disease in the domestic feline and canine have been
exposed to high doses of the TSE prion disease vid pet food. To date, it’s still
legal to include deer from cwd zone into pet food or deer food. Specified Risk
Material i.e. SRM bans still being breach, as recently as just last month.

nvCJD or what they now call vCJD, another case documented in Texas last
month, with very little information being released to the public on about this
case? with still the same line of thought from federal officials, ‘it can’t
happen here’, so another vCJD blamed on travel of a foreign animal disease from
another country, while ignoring all the BSE TSE Prion risk factors we have here
in the USA and Canada, and the time that this victim and others, do spend in the
USA, and exposed to these risk factors, apparently do not count in any way with
regard to risk factor. a flawed process of risk assessment.

sporadic CJD, along with new TSE prion disease in humans, of which the
young are dying, of which long duration of illness from onset of symptoms to
death have been documented, only to have a new name added to the pot of prion
disease i.e. sporadic GSS, sporadic FFI, and or VPSPR. I only ponder how a
familial type disease could be sporadic with no genetic link to any family
member? when the USA is the only documented Country in the world to have
documented two different cases of atypical H-type BSE, with one case being
called atypical H-G BSE with the G meaning Genetic, with new science now showing
that indeed atypical H-type BSE is very possible transmitted to cattle via oral
transmission (Prion2014). sporadic CJD and VPSPR have been rising in Canada,
USA, and the UK, with the same old excuse, better surveillance. You can only use
that excuse for so many years, for so many decades, until one must conclude that
CJD TSE prion cases are rising. a 48% incease in CJD in Canada is not just a
blip or a reason of better surveillance, it is a mathematical rise in numbers.
More and more we are seeing more humans exposed in various circumstance in the
Hospital, Medical, Surgical arenas to the TSE Prion disease, and at the same
time in North America, more and more humans are becoming exposed to the TSE
prion disease via consumption of the TSE prion via deer and elk, cattle, sheep
and goats, and for those that are exposed via or consumption, go on to further
expose many others via the iatrogenic modes of transmission of the TSE prion
disease i.e. friendly fire. I pondered this mode of transmission via the victims
of sporadic FFI, sporadic GSS, could this be a iatrogenic event from someone
sub-clinical with sFFI or sGSS ? what if?

Two decades have passed since Dr. Ironside first confirmed his first ten
nvCJD victims in 1995. Ten years later, 2005, we had Dr. Gambetti and his first
ten i.e. VPSPR in younger victims. now we know that indeed VPSPR is
transmissible. yet all these TSE prion disease and victims in the USA and Canada
are being pawned off as a spontaneous event, yet science has shown, the
spontaneous theory has never been proven in any natural case of TSE prion
disease, and scientist have warned, that they have now linked some sporadic CJD
cases to atypical BSE, to atypical Scrapie, and to CWD, yet we don’t here about
this in the public domain. We must make all human and animal TSE prion disease
reportable in every age group, in ever state and internationally, we must have a
serious re-evaluation and testing of the USA cattle herds, and we must ban
interstate movement of all cervids. Any voluntary effort to do any of this will
fail. Folks, we have let the industry run science far too long with regards to
the TSE prion disease. While the industry and their lobbyist continues to funnel
junk science to our decision policy makers, Rome burns. ...end

REFERENCES

[all scientific peer review studies and other scientific information I have
put into blogs, to shorten reference data. I DO NOT advertise or make money from
this, this information is for education use...lost my mom to the hvCJD, and just
made a promise, never forget, and never let them forget. ...TSS]

The propensity for trans-species prion transmission is related to the
structural characteristics of the enciphering and heterologous PrP, but the
exact mechanism remains mostly mysterious. Studies of the effects of primary or
tertiary prion protein www.landesbioscience.com Prion 37 structures on
trans-species prion transmission have relied upon animal bioassays, making the
influence of prion protein structure vs. host co-factors (e.g. cellular
constituents, trafficking, and innate immune interactions) difficult to dissect.
As an alternative strategy, we are using real-time quaking-induced conversion
(RT-QuIC) to investigate the propensity for and the kinetics of trans-species
prion conversion. RT-QuIC has the advantage of providing more defined conditions
of seeded conversion to study the specific role of native PrP:PrPRES
interactions as a component of the species barrier.

We are comparing chronic wasting disease (CWD) and bovine spongiform
encephalopathy (BSE) prions by seeding each prion into its native host recPrP
(full-length bovine recPrP, or white tail deer recPrP) vs. into the heterologous
species. Upon establishing the characteristics of intra-species and
inter-species prion seeding for CWD and BSE prions, we will evaluate the seeding
kinetics and cross-species seeding efficiencies of BSE and CWD passaged into a
common new host—feline—shown to be a permissive host for both CWD and BSE.

*** We hypothesize that both BSE prions and CWD prions passaged through
felines will seed human recPrP more efficiently than BSE or CWD from the
original hosts, evidence that the new host will dampen the species barrier
between humans and BSE or CWD. The new host effect is particularly relevant as
we investigate potential means of trans-species transmission of prion disease.

The Committee met on October 22, 2013 at the Town and Country Hotel, San
Diego, California, from 9:00 to 11:46 a.m. There were 12 members and 9 guests
present. The meeting began with a review of the of the Committee purpose.

Attendees did not elect to make any changes to the current language. The
following presentations and reports were given.

• There has been a 90 percent decrease in the percent positive sheep
sampled at slaughter adjusted for face color, from 0.15 to 0.015 percent, since
the start of Regulatory Scrapie Slaughter Surveillance (RSSS) in FY 2003 thru
September 30, 2013.

• There were 11 new infected or source flocks reported in FY 2013 as of
September 30, 2013. FY 2013 is the first year since FY 2005 when a reduction in
the number of new scrapie infected and source flocks was not observed. Now that
the program is in the tail end of the eradication effort it is likely that the
numbers will go up and down from year to year due to the difficulty in
accurately measuring the frequency of uncommon events. Slaughter
Surveillance

• The number of animals sampled through slaughter surveillance in FY 2013,
through September 30, 2013 was 42,888 compared to 40,776 in FY 2012; this
represents an increase of 5 percent. The increase was due to increased sampling
of goats.

Scrapie Surveillance Plan

• Implementation

o States with regulatory scrapie slaughter surveillance (RSSS) collection
sites will continue to sample all targeted sheep and goats.

o The annual State-of-origin sampling minimum for sheep is 20 percent of
the number required to detect a scrapie prevalence of 0.1 percent with 95
percent confidence or 1 percent of the breeding flock in the State, whichever is
less. The objective is to sample sufficient sheep in a 5-year period to detect a
scrapie prevalence of 0.1 percent with 95 percent confidence or 5 percent of the
breeding flock in the State, whichever is less.

o The annual State-of-origin sampling minimum for goats is determined based
on the States’ goat scrapie case incidence.

o If a State has not had a goat scrapie case in the previous ten years, its
annual goat sampling minimum is its prorated share of 3,000 samples, based on
its proportion of the U.S. goat population as determined by the National
Agricultural Statistics Survey (NASS) Sheep and Goat annual report.

o If a State has had a goat scrapie case in the previous ten years, its
annual goat sampling minimum is determined using the same method as is used for
determining its annual sheep sampling minimum.

o Beginning in FY 2013, sheep and goat sampling minimums were calculated
separately. As a result, a higher percentage of States will not achieve their
sheep sampling minimums in FY 2013 compared with FY 2012. Approximately 40% will
not achieve the sheep sampling minimums this fiscal year, compared to
approximately 20% in FY 2012. States that did not meet their sheep sampling
minimum in FY 2013 through RSSS but will be expected to find other sampling
sources to meet the minimum in FY 2014.

Note: These are minimums. Plans are to continue to collect samples from the
maximum number of targeted animals given the available budget.

FY 2014 Priorities

• VS priorities for scrapie are to focus on improving the effectiveness and
cost efficiency of surveillance and to increase animal identification
compliance. This will be accomplished in part by publishing a proposed rule that
would address gaps in identification and require States to meet reasonable
surveillance targets to remain consistent States. States must meet these targets
for VS to demonstrate geographically appropriate surveillance to meet the
criteria for freedom and have confidence that all of the remaining cases have
been found.

• The rule would propose to:

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o Give the APHIS Administrator authority to relieve requirements for sheep
and goats exposed to scrapie types, such as Nor98-like, that do not pose a
significant risk of transmission;

o Increase flexibility in how investigations can be conducted and allow the
epidemiology in a specific flock to be given more consideration in determining
flock and animal status;

o Add a genetic-based approach to regulation;

o Make goat identification requirements similar to those for sheep to
support ongoing slaughter surveillance in goats (no changes will be made in the
consistent State requirements regarding identification of goats in intrastate
commerce);

o Limit the use of tattoos and implants to animals not moving through
markets and not in slaughter channels; and

o Reduce recordkeeping requirements by making them similar to the current
uniform methods and rules compliance guidance.

• APHIS is also revising its scrapie import regulations to bring them more
in line with the World Animal Health Organization (OIE) scrapie chapter. This
will ensure that we meet OIE criteria for free status and prevent the
reintroduction of scrapie after free status is achieved.

Scrapie Flock Certification Program (SFCP) Standards

On May 3, 2013 APHIS announced its intention to revise the SFCP. The
comment period closed June 3, and the revised program has gone into effect. The
SFCP standards were revised to increase the program’s ability to identify
infected flocks quicker and to prevent infected flocks from becoming certified,
to reduce costs associated with the program, and to increase SFCP contribution
to scrapie surveillance. Scrapie program staff collected input from SFCP
enrolled producers, industry representatives, and State and federal
stakeholders. The public had a final opportunity to comment on the revised
standards through a Federal Register notice.

In the revised SFCP the Complete category is eliminated. Additionally, the
Select category is revised, and the Export category is slightly modified.

• Select category: APHIS has redirected monitoring from inspections to
sampling. Select category flocks do not become certified. Specifics for this
category include:

o Flock owners can acquire animals from any other flock, whether or
not

REPORT OF THE COMMITTEE

342

that flock is enrolled in the SFCP.

o The sampling and testing requirements include:

 Sheep or goats displaying clinical signs over 12 months of age;

 Animals of any age that either test suspect, inconclusive or positive on
a live animal scrapie test or have been determined to be a scrapie suspect by a
State, Federal or accredited veterinarian; and  A minimum of one animal per 1-3
years, depending on flock size.

• Export Category: APHIS continues a high level of monitoring including
inspections and sampling. Flocks can become Export Certified. Specifics for this
category include:

o Annual inspections are required.

o Owners must report clinical signs of scrapie.

o Animals must be identified with official SFCP ID.

o Flock owners must meet rigorous recordkeeping requirements including
maintaining records on every animal that leaves the flock for seven years.

o Flock owners must have all cull animals inspected, including home
slaughtered animals, for clinical signs of scrapie at least 30 days before
culling.

o Flock owners can acquire female animals and embryos only from other
Export category flocks of equal or higher status.

o Flock owners can use sheep and goat milk and colostrum and sheep and goat
milk- and colostrum-derived products only from within their own flock or from
other Export category flocks of equal or higher status.

o The sampling and testing requirements include:

 Sheep or goats displaying clinical signs over 12 months of age;

 Animals of any age that either test suspect, inconclusive or positive on
a live animal scrapie test or have been determined to be a scrapie suspect by a
State, Federal or accredited veterinarian;

 All found dead mature animals, including euthanized animals;

 An annual sampling minimum of one test eligible animal tested for each
year of status held (A flock will be removed from the program if the flock owner
fails to submit at least one test eligible animal for two consecutive
years.);

 To gain six years in status, 15 test eligible animals must be sampled;
and

 The requirements for Export Certified status include:

 seven years in status; and

 Meet one of three sampling protocols

o Standard: 30 test eligible animals

o Alternative 1: test all genetically susceptible animals sold

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o Alternative 2: test all foundation flock animals.

• Participants in the Complete category had the following options: (1) join
the Export category with up to 5 years of status; (2) join the revised Select
category; or (3) withdraw from the program.

o For participants who held “Certified” status in the Complete category who
convert to the Export category, APHIS will continue to publish their “Certified”
status on its website for 3 years following the start date of the revised
program, in addition to their new “Export Monitored” status, to allow them
sufficient time to become Export Certified; and

o If instead they convert to the Select category or withdraw from the
program, APHIS will not continue to publish their “Certified” status on its
website.

Scrapie Surveillance Projects:

• Since the start of slaughter surveillance in 2003 the prevalence of
scrapie in sheep has declined 85 percent from 0.2 percent to less than 0.03
percent. The prevalence in goats is estimated to be less than 0.02
percent.

• In FY 2013 APHIS initiated an effort to provide information on sample
collection and to encourage producer and accredited veterinarian submission of
samples.

• Instructions for producers and veterinarians to submit samples are now
available on the APHIS Scrapie Web Page.

• In FY 2014 APHIS will conduct pilot projects in New Jersey and Arkansas
to evaluate the efficiency of working with accredited veterinarians to collect
samples for scrapie testing.

Update from Agriculture Research Service

David Schneider

USDA, Agriculture Research Service (ARS), Animal Disease Research Unit
(ADRU)

The USDA-ARS unit in Pullman, Washington, conducts an integrated research
program involving studies on scrapie transmission, diagnosis and susceptibility
genetics in domestic sheep and goats. Accumulation of disease-associated prion
protein (PrPSc) in the placenta of sheep is a recognized source for natural
transmission of classical scrapie disease and environmental contamination. Much
less is known about prion accumulation in the placenta of goats but our recent
study demonstrated much less PrPSc accumulates in the placenta in goats, which
calls into question its role in natural transmission. In a recent follow-up
study, we now demonstrate that the placenta of goats does harbor prions
infectious to other goats and sheep when exposed by the oral route. A study on
Nor98-like scrapie in breeding ewes is now in its 6th year.

REPORT OF THE COMMITTEE

344

Ewes were experimentally inoculated with brain homogenate obtained from a
U.S. sheep with clinical Nor98-like scrapie. Recipient ewes are bred annually to
examine the placenta for evidence of a transmissible agent. Placentas shed
2009-2013 were negative. In 2013, one recipient ewe developed an unrelated
disease. At postmortem examination, abundant accumulation of PrPSc was observed
only in the cerebellum of this ewe with much less accumulation in the hindbrain
obex. This confirms that initial inoculation of these ewes has been successful.
Monitoring continues in the remaining ewes of this study. Improvements in
tissue-based (rectal biopsy) live animal testing for scrapie with focus on
application to goats continue. In addition, efforts toward developing a
live-animal blood test have demonstrated the presence of prions (infectivity) in
the blood of sheep and goats, even those with preclinical disease and within
blood sample volumes routinely used in veterinary diagnostic work. A recent
study also demonstrates PrPSc accumulation in lymphoid tissues of hemal nodes,
small lymphoid organs that filter blood but not lymph. Collectively, these
findings confirm that blood is a relevant target for continued assay
development. We continue to develop methods for enriching the relevant blood
fractions for assay and are now making efforts to adapt novel in vitro assays
for detecting infectivity and prion-associated misfolding activity. A long term
study examining the effect of prion genotype on susceptibility to goat scrapie
and the effect of genetic changes on accuracy of live animal testing continue.
Following oral infection at birth with placenta and brain-derived scrapie, goats
with the highly susceptible genotype all developed clinical disease around 24
months. Goats with the less susceptible or long incubation genetics today remain
clinically normal. Monitoring continues.

Prion Transmission Through Milk

Christina Sigurdson

University of California, San Diego School of Medicine, Department of
Pathology

Prion disorders are caused by misfolded proteins that are naturally
transmitted, causing a fatal neurological disease in animals. In sheep with
classical scrapie, prions accumulate in the follicles of lymphoid tissues in
addition to the brain and spinal cord. Follicular dendritic cells (FDCs) form a
network within the follicles and accumulate high levels of prions during
disease. Previous work in mice has revealed that follicular inflammation in
non-lymphoid organs, such as kidney, results in prion accumulation and can lead
to prion shedding, such as into the urine. We have found sheep with follicular
mastitis and scrapie that have accumulated prions within the follicles of the
mammary gland.

In follow-up studies, we found that sheep with scrapie and lentiviral
mastitis secrete prions into the milk and infect nearly 90% of naïve suckling
lambs. Taken together, lentiviruses may enhance prion transmission and
conceivably sustain prion infections in flocks for generations. Work by other
groups has also shown prion infectivity in all three milk fractions, cells,
casein whey, and cream. Prion infectivity has also been detected in milk from
sheep having the VRQ/VRQ genotype with no evidence of mastitis.

The final response from the Committee’s 2012 Resolution (26, 9 and 30
Combined) relating to the export of sheep and goats was reviewed. In this
response the USDA-APHIS-VS agreed to ask the World Organization for Animal
Health (OIE) to modify the Scrapie Chapter to consider options such as
genotyping to qualify animals for export. USDA-APHIS-VS agreed to make this
request by Spring 2014, and would expect to see the Scrapie Chapter amended in
Spring 2015 or 2016 if their revisions were to be accepted by OIE.

One of the Committee members updated the group on progress related to a
2010 Resolution #48. This resolution requested USDA, Food Safety Inspection
Service (FSIS) to work with USDA-APHIS-VS and industry to identify and approve
appropriate sites for radio frequency identification implants for goats and
sheep. As a result, both the underside of the tail and the base of the ear are
now approved sites for these implants. No new resolutions or recommendations
were introduced.

The Committee briefly discussed the challenges of obtaining scrapie
surveillance samples from certain flocks and herds. Several members mentioned
that one barrier to sample collection is the problem that the producers have
with carcass disposal after the head has been removed. Members agreed that
offering options to producers to help them properly dispose of these carcasses
could significantly increase voluntary participation in surveillance. Options
include to transporting carcasses to diagnostic laboratories or providing
payment to the producers to offset the cost of carcass disposal.

RESOLUTION NUMBER: 22 – APPROVED

SOURCE: COMMITTEE ON SHEEP AND GOATS

SUBJECT MATTER: SEPARATE SHEEP AND GOAT COMMODITY HEALTH LINE ITEM

BACKGROUND INFORMATION:

In FY2011, the United States Department of Agriculture (USDA), Animal and
Plant Health Inspection Service (APHIS), Veterinary Services (VS) primarily
addressed sheep and goat health/disease issues through the National Scrapie
Eradication Program (NSEP) and National Animal Health Monitoring System (NAHMS)
studies. For FY2012, USDA-APHIS-VS requested that Congress approve
commodity-based funding which would include horses, cervids, sheep, and goats in
a single line item where funding could be transferred between the commodities
based on priorities identified by USDA-APHIS-VS and its partners. The proposed
grouping of these species is reminiscent of the failed Miscellaneous Diseases
line item in the USDA-APHIS-VS budget of over 20 years ago.

NOMINATIONS AND RESOLUTIONS

293

The United States Animal Health Association is concerned that sheep and
goat funding may be diverted to address needs of other species, which could
jeopardize the eradication of scrapie from the United States and the health and
well-being of sheep and goats.

The currently proposed species grouping of Equines, Cervids, and Small
Ruminants (sheep and goats) is not appropriate to serve the health and disease
needs of such a diverse group of animals. Equines and Cervids have very few
common health and disease issues with Sheep and Goats. Emerging diseases in each
of the species in the proposed grouping will most likely result in even less
commonality in disease/health priorities among these species.

RESOLUTION:

The United States Animal Health Association (USAHA) urges the United States
Department of Agriculture (USDA), Animal and Plant Health Inspection Service
(APHIS), Veterinary Services (VS) to establish a separate funding line item for
Sheep and Goat Health.

The Committee met on October 22, 2013 at the Town and Country, San Diego,
California, from 1:00 to 4:30 p.m. There were 9 members and 12 guests present.
The meeting proceeded with the following presentations and reports.

Overview of Schmallenburg Virus: Lessons from a European Outbreak

Rob Cordery-Cotter, Dept. of Animal Science, University of Wyoming

Dr. Cordery-Cotter presented the history of Schmallenberg Virus (SBV)
incursion into Europe and the United Kingdom (U.K.), with excellent photos and
case histories of clinical signs and symptoms. A complete power point of this
presentation is available on the Committee web page, at www.usaha.org.

Regulatory Updates for Sheep and Goat Importations

Joyce Bowling-Heyward, NCIE, USDA-APHIS

Discussion initiated with discussion of bovine spongiform encephalopathy
(BSE), Scrapie and other Transmissible spongiform encephalopathies (TSEs) in
Ruminants, and impact on regulations concerning these. Schmallenburg Virus and
potential for incursion was discussed, and need for surveillance and vigilance.
A complete copy of this presentation is included at the end of this report.

Chronic Wasting Disease CWD

Goals for CWD Herd Certification Program

Lee Ann Thomas, Ruminant Health Programs, USDA-APHIS–VS

An overview was presented of the voluntary national Chronic Wasting Disease
(CWD) herd certification program for farmed deer, elk, and moose as well as
established minimum standards for interstate movement of cervids. The purpose of
the Herd Certification Program (HCP) is to provide clarification and guidance on
how to comply with and meet requirements of the CWD rule and contains two Parts:
Part A – Herd Certification and Part B – Guidance on Response to CWD-affected
herds.

Funding for the program is through APHIS-VS Equine, Cervids, Small
Ruminants (ECSR) Commodity Health Line which funds essential activities for
surveillance and program operations with flexibility to respond to new and
emerging health concerns.

A review of the FY 2013/14 Program Activities of APHIS-VS which included
federal oversight of the voluntary national CWD HCP as well as the principle
activities conducted that pertain to the HCP.

Based on available resources, APHIS will serve in an advisory capacity to
Approved States for 1) epidemiological investigations of positive findings; 2)
development of herd plans (newly infected herds); 3) quarantine, depopulations,
cleaning and disinfection; and 4) assistance with annual herd inspections and
tri-annual physical herd inventories.

The CWD Interim Final Rule (CWD Herd Certification Program and Interstate
Movement of Farmed or Captive Deer, Elk, and Moose) was published in the Federal
Register June 13, 2012 with a public comment period. The effective date of the
rule was August 13, 2012.

Part 81 of the Rule delayed enforcement until December 10, 2012. Public
comments have been considered and affirmation of a final rule is in development.
The Revised federal rule applies only to the following genera known to be
susceptible to CWD by natural infection including, Cervus (elk, red deer, sika
deer), Odocoileus (white-tailed deer (WTD), mule deer (MD), black-tailed deer
(BTD) and Alces (moose). States may have requirements for other cervid
species.

States having a CWD HCP may request federal approval of their State program
which will be approved by APHIS in accordance with CWD rule (9 CFR 55.23). As of
October 2013, there are 29 Approved State HCPs. Approved states must have a
signed memorandum of understanding (MOU) with APHIS that addresses 1) authority
to restrict animal movement; 2) enforces and monitors quarantines; 3)
surveillance and disease reporting capability; 4) animal identification; 5)
designated CWD HCP coordinator; 6) mortality surveillance; 7) recordkeeping and
data management; 8) ability to conduct epidemiologic investigations; 8)
education/ outreach for producers; 9) herd plans (CWD positive/exposed herds);
and 10) annual reports to renew Approved status.

Herd owners already participating in State CWD programs will keep initial
State enrollment date (first date of participation) when State is designated an
Approved State CWD HCP. There is no available funding projected for FY2014 to
support direct herd owner enrollment in the national program. Herd owners must
comply with animal identification, fencing requirements, reporting escapes &
mortalities and mortality testing for certified status, herd records and
inventories, separation from other herds, and status of herd additions.

A CWD Working Group was formed to review and provide input on revisions to
the CWD Program Standards (2012 USAHA Resolution). Members included
representatives from the cervid industry, state animal health officials, state
wildlife agencies/ Association of Fish and Wildlife Agencies (AFWA), and
diagnostic laboratories (AAVLD/NAHLN), and APHIS-VS. Meetingwere conducted
through weekly teleconferences and topics discussed included – physical
inventory, sample collection, missing samples, reporting mortalities and
escapes, transiting, herd plans, trace outs, animal identification, fencing, and
interstate movement.

There was one resolution presented and passed by the Committee regarding a
National Review of Research Needs for Chronic Wasting Disease. The resolution
was submitted requesting that the USAHA request the USDA, and the U.S.
Department of Interior (DOI) to arrange a diversified blue-ribbon panel (which
would include industry stakeholders, university and federal researchers, and
Federal and State regulatory agencies) to determine research needs and identify
and prioritize intervention strategies for the control of Chronic Wasting
Disease. The resolution was moved by member Warren Bluntzer and seconded by Glen
Zebarth, and forwarded to the Committee on Nominations and Resolutions.

A recommendation was presented to the Committee on Captive Wildlife and
Alternative Livestock to create a new Committee on farmed cervidae. The motion
to form the new Committee was moved by Richard Winters and seconded by Paul
Anderson. A vote following discussion was tied 13 to 13. The following is a copy
of the recommendation with some preliminary edits. It was felt by many of the
members that if this Committee was approved that there should be some
significant modifications to the mission statement, which was proposed as
follows:

Background:

The farmed cervidae industry is unique in that producers deal with
diseases, regulations and political issues which are unlike any other animal
agricultural industry.

To effectively address these issues requires a national forum for
discussion. The creation of a new USAHA committee where farmed cervidae
producers can work together with state and federal regulatory officials and
scientists to solve the problems faced by the industry is critical.

Mission:

“The purpose of the Committee on Farmed Cervidae is to provide a national
forum to (1) discuss scientific, regulatory and political issues affecting the
farmed cervidae industry, (2) evaluate state and federal regulatory programs,
(3) develop effective programs to control diseases, and (4) recommend regulatory
programs that contribute to the growth and prosperity of the farmed cervidae
industry while mitigating disease risks.” The Committee adjourned at 12:47 p.m.

RESOLUTION NUMBER: 16 – APPROVED

SOURCE: COMMITTEE ON CAPTIVE WILDLIFE AND ALTERNATIVE LIVESTOCK

SUBJECT MATTER: NATIONAL REVIEW OF RESEARCH NEEDS FOR CHRONIC WASTING
DISEASE

BACKGROUND INFORMATION:

In the absence of an approved live animal test, vaccine, or recognition of
genetically resistant animals, depopulation and indemnity of the herd mates
is

NOMINATIONS AND RESOLUTIONS

289

our only method of prevention to stop the spread of Chronic Wasting Disease
(CWD) to other animals.

A Federal CWD Rule has been implemented with the purpose of controlling the
spread of CWD versus eradication. To insure a successful program more tools are
needed to manage this disease.

RESOLUTION:

The United States Animal Health Association (USAHA) requests that the
United States Department of Agriculture, and United States Department of
Interior arrange a diversified blue-ribbon panel (including: industry
stakeholders, university and federal researchers, Federal and State regulatory
agencies) to determine research needs and identify and prioritize intervention
strategies for the control of Chronic Wasting Disease.

Dr. Brant Schumaker of the University of Wyoming reported that the effects
of high chronic wasting disease (CWD) prevalence in free-ranging deer
populations are unknown. In south-central Wyoming, CWD prevalence exceeds 50% in
hunter harvested deer. We hypothesized that 1) vital rates are depressed by CWD
and the finite rate of population growth (λ) is subsequently lowered, 2) CWD
alters normal deer behavior during preclinical and clinical disease, and 3)
genetic differences associated with CWD incubation periods drives natural
selection to favor less susceptible deer. To test these hypotheses, we
radio-collared white-tailed deer (Odocoileus virginianus) and mule deer
(Odocoileus hemionus) and monitored them to determine a) survival probability,
pregnancy rates, and annual recruitment, b) cause of death, c) home range area
and habitat use, d) migration patterns, e) dispersal behavior, and f) genetic
variation in incubation period based on CWD-status. Deer were tested for CWD
using tonsil tissue collected by biopsy at capture and immunohistochemistry.
White-tailed deer positive for CWD were 4.5 times more likely to die annually
compared to CWD-negative deer. High CWD prevalence depressed survival of young
females and resulted in an unsustainable white-tailed deer population (λ <
1.0); however, when female harvest was eliminated, the population became stable
(λ =1.0). Female CWD-positive white-tailed deer maintain locally high CWD
incidence as they migrated less and occupied smaller home ranges compared to
other deer. Male CWD-positive white-tailed deer migrated at the highest
proportion and likely contributed to spread of CWD to disparate populations. In
the last nine years, mule deer genetically associated with prolonged incubation
periods to CWD have increased in frequency in the population. However, it is
still unknown whether or not this change will counteract the negative impacts of
CWD on the population. The white-tailed deer population is adversely affected by
high CWD prevalence; however, implementing management techniques to increase
annual survival of females may maintain deer populations. The impact of CWD on
mule deer populations is currently unknown; however, the present study is in its
final stages with results to be completed in the near future.

snip...

BSE

A comment was posted regarding bovine spongiform encephalopathy (BSE)
indicating the possible need to review the present protocol for renderers so
that carcasses which are submitted for rabies, are flagged at the render and
held until testing for rabies and BSE is completed.

Regulatory Updates for Sheep and Goat Importations

Joyce Bowling-Heyward, NCIE, USDA-APHIS

Discussion initiated with discussion of bovine spongiform encephalopathy
(BSE), Scrapie and other Transmissible spongiform encephalopathies (TSEs) in
Ruminants, and impact on regulations concerning these. Schmallenburg Virus and
potential for incursion was discussed, and need for surveillance and vigilance.
A complete copy of this presentation is included at the end of this report.

A recommendation was presented to the Committee on Captive Wildlife and
Alternative Livestock to create a new Committee on farmed cervidae. The motion
to form the new Committee was moved by Richard Winters and seconded by Paul
Anderson. A vote following discussion was tied 13 to 13. Attached is a copy of
the recommendation with some preliminary edits in track changes. It was felt by
many of the Committee members that if this committee was approved that there
should be some significant modifications to the mission statement, which was
proposed as follows: Background:

The farmed cervidae industry is unique in that producers deal with
diseases, regulations and political issues which are unlike any other animal
agricultural industry.

To effectively address these issues requires a national forum for
discussion. The creation of a new USAHA committee where farmed cervidae
producers can work together with state and federal regulatory officials and
scientists to solve the problems faced by the industry is critical. Mission:

“The purpose of the Committee on Farmed Cervidae is to provide a national
forum to

Background. CWD is a disease affecting wild and farmraised cervids in North
America. Epidemiological studies provide no evidence of CWD transmission to
humans. Multiple attempts have failed to infect transgenic mice expressing human
PRNP gene with CWD. The extremely low efficiency of PrPCWD to convert normal
human PrPC in vitro provides additional evidence that transmission of CWD to
humans cannot be easily achieved. However, a concern about the risk of CWD
transmission to humans still exists. This study aimed to establish and
characterize an experimental model of CWD in TgSB3985 mice with the following
attempt of transmission to TgHu mice.

Materials and Methods. TgSB3985 mice and wild-type FVB/ NCrl mice were
intracranially injected with 1% brain homogenate from a CWD-infected Tga20 mouse
(CWD/Tga20). TgSB3985 and TgRM (over-expressing human PrP) were similarly
injected with 5% brain homogenates from CWD-infected white-tailed deer (CWD/WTD)
or elk (CWD/Elk). Animals were observed for clinical signs of neurological
disease and were euthanized when moribund. Brains and spleens were removed from
all mice for PrPCWD detection by Western blotting (WB). A histological analysis
of brains from selected animals was performed: brains were scored for the
severity of spongiform change, astrogliosis, and PrPCWD deposition in ten brain
regions.

Results. Clinical presentation was consistent with TSE. More than 90% of
TgSB3985 and wild-type mice infected with CWD/Tga20, tested positive for PrPres
in the brain but only mice in the latter group carried PrPCWD in their spleens.
We found evidence for co-existence or divergence of two CWD/ Tga20 strains based
on biochemical and histological profiles. In TgSB3985 mice infected with CWD-elk
or CWD-WTD, no animals tested positive for PrPCWD in the brain or in the spleen
by WB. However, on neuropathological examination we found presence of amyloid
plaques that stained positive for PrPCWD in three CWD/WTD- and two
CWD/Elk-infected TgSB3985 mice. The neuropathologic profiles in CWD/WTD- and
CWD/Elkinfected mice were similar but unique as compared to profiles of BSE,
BSE-H or CWD/Tg20 agents propagated in TgSB3985 mice. None of CWD-infected TgRM
mice tested positive for PrPCWD by WB or by immunohistochemical detection.

Conclusions. To our knowledge, this is the first established experimental
model of CWD in TgSB3985. We found evidence for co-existence or divergence of
two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice.
Finally, we observed phenotypic differences between cervid-derived CWD and
CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway
to characterize these strains.

An intrinsic property of prions is their extreme resistance to degradation.
When they are deposited within the environment, whether from inappropriate
disposal by man or from fallen diseased livestock, there is the potential to
further propagate cases of disease for many years. It is evidenced that the
spread of scrapie in sheep and chronic wasting disease in deer have occurred in
this manner.

We mimicked such scenarios under large-scale field conditions to determine
the extent to which TSE infectivity survives or disseminates in soil and soil
water over five years. The mouse passaged BSE strain, 301V, was used to spike
buried bovine heads, or was buried as an uncontained bolus in large soil-filled
lysimeters. Two soils were examined, a free-draining sandy loam and a
water-retentive clay loam.

Infectivity, determined by bioassay in mice, was recovered from all heads
exhumed annually for 5 years from both soil types, with little reduction in the
amount of infectivity over time. Small amounts of infectivity were found in soil
samples immediately surrounding the heads but not in samples remote from them.
Commensurate with this there was no evidence of significant lateral movement of
infectivity from the bolus buried in a large soil mass. However large amounts of
infectivity were recovered at the original bolus burial site in both soils.
There was limited vertical upward movement of infectivity from the bolus buried
in clay and downward movement from the bolus buried in sand perhaps reflecting
the clay soils propensity to flood.

Throughout the course of the experiment rainwater particulate from several
lysimeters was trapped on glass-fibre filters. Extracts from these filters were
subject to serial PMCA (protein misfolding cyclic amplification) which was
optimised using 301V-spiked samples and blinded controls. All positive and
negative control samples were correctly determined. We have tested 44 samples
from rainwater passed through the clay lysimeter filters, and found 9 positive
samples, mainly from the initial 8 months of the experiment.

We conclude that TSE infectivity is likely to survive burial for long time
periods with minimal loss of infectivity and limited movement from the original
burial site. However PMCA results have shown that there is the potential for
rainwater to elute TSErelated material from soil which could lead to the
contamination of a wider area. These experiments reinforce the importance of
risk assessment when disposing of TSE risk materials.

Chronic wasting disease (CWD) is a prion disorder effecting captive and
free-ranging deer and elk. The efficient propagation suggests that horizontal
transmission through contaminated environment may play an important role. It has
been shown that infectious prions enter the environment through saliva, feces,
urine, blood or placenta tissue from infected animals, as well as by carcasses
from diseased animals and can stay infectious inside soil over several
years.

82 Prion Volume 8 Supplement

We hypothesize that environmental components getting in contact with
infectious prions can also play a role for the horizontal transmission of prion
diseases. To study this issue, surfaces composed of various environmentally
relevant materials were exposed to infectious prions and the attachment and
retention of infectious material was studied in vitro and in vivo. We analyzed
polypropylene, glass, stainless steel, wood, stone, aluminum, concrete and brass
surfaces exposed to 263K-infected brain homogenate. For in vitro analyses, the
material was incubated in serial dilutions of 263K-brain homogenate, washed
thoroughly and analyzed for the presence of PrPSc by PMCA. The results show that
even highly diluted PrPSc can bind efficiently to polypropylene, stainless
steel, glass, wood and stone and propagate the conversion of normal prion
protein. For in vivo experiments, hamsters were ic injected with implants
incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with
263K-contaminated implants of all groups, developed typical signs of prion
disease, whereas control animals inoculated with non-contaminated materials did
not.

In addition, in order to study the transmission in a more natural setting,
we exposed a group of hamster to habit in the presence of spheres composed of
various materials that were pretreated with 263K prions. Many of the hamsters
exposed to these contaminated materials developed typical signs of the disease
that were confirmed by immunohistological and biochemical analyses.

These findings suggest that various surfaces can efficiently bind
infectious prions and act as carriers of infectivity, suggesting that diverse
elements in the environment may play an important role in horizontal prion
transmission.

Chronic wasting disease (CWD), a prion disease of cervids (deer, elk and
moose), is spreading unchecked through large sections of North America.
Transmission of CWD among cervids is especially facile and can occur through
direct animal-toanimal contact and indirectly through contact with prions shed
from infected animals. The disease transmission threat posed by CWD to other
wildlife species remains unknown, but other species are inevitably exposed to
CWD by consumption of infectious materials and through contact with
environmental CWD contamination.

In this study, we investigated the transmission and adaptation of various
white-tailed deer CWD isolates in the meadow vole (Microtus pennsylvanicus), a
native North American rodent that is sympatric with current CWD epizootics that
we have previously established is susceptible to CWD. We found that serial
subpassage of CWD from white-tailed deer homozygous for glycine at position 96
(96GG) of the prion protein in meadow voles resulted in the selection of a
single prion strain that was characterized by homogeneity in incubation period,
abnormal prion protein (PrPTSE) glycoform ratio, lesion profile and PrPTSE
deposition pattern. In contrast, passage of CWD from heterozygous 96GS genotype
deer produced four unique disease phenotypes upon first passage. Subpassage of
these types ultimately resulted in selection of a single strain by third passage
that was distinct from the 96GG genotype CWD-derived strain.

We also establish that meadow voles are susceptible to CWD via peripheral
challenge, albeit with lower attack rates and longer incubation periods.
Interestingly, oral challenge of meadow voles with CWD resulted in subclinical
infection in primary passage animals, but manifested as clinical prion disease
upon subpassage.

Our data establish that meadow voles are permissive to CWD via peripheral
exposure route, suggesting they could serve as an environmental reservoir for
CWD. Additionally, our data are consistent with the hypothesis that at least two
strains of CWD circulate in naturally-infected cervid populations and provide
evidence that meadow voles are a useful tool for CWD strain typing.

Background/Introduction. Chronic wasting disease (CWD) is unique among
prion diseases in its efficient lateral transmission in nature. While the
presence of infectious prions in body fluids and excreta of infected cervids has
been demonstrated by bioassay, the dynamics, magnitude, and consequences of
prion shedding remain unknown. The present studies were undertaken to determine
the kinetics, duration, and magnitude of prion shedding in infected white-tailed
deer.

Materials and Methods. Longitudinal samples were collected from
white-tailed deer over a 2-year span after either oral (n=11)] aerosol (n = 6)
CWD exposure. The assay protocol employed phosphotungstic acid precipitation of
either whole saliva or the pelleted fraction of urine to seed recombinant Syrian
hamster prion PrP substrate in RT-QuIC reactions. Prion seeding activity was
assayed in 8 replicates of each sample employing thioflavin T detection in a
96-well plate-based fluorometer. Prion seeding reaction rate was determined by
taking the inverse of the time at which samples exceeded a threshold of 5
standard deviations above the mean fluorescence of negative controls (1/time to
threshold). Seeding activity was quantitated by comparing the realtime
conversion reaction rate to a standard curve derived from a reference bioassayed
brain pool homogenate from deer with terminal CWD.

Results. We analyzed >200 longitudinally collected, blinded, then
randomized saliva and urine samples from 17 CWDinfected and 3 uninfected
white-tailed deer. We detected prion shedding as early as 3 months post exposure
and sustained thereafter throughout the disease course in both aerosol and
orally exposed deer. The incidence of non-specific false positive results from
>500 saliva and urine samples from negative control deer was 0.8%. By
comparing real-time reaction rates for these body fluids to a bioassayed
serially diluted brain control, we estimated that ≤1 ml of saliva or urine from
pre-symptomatic infected deer constitutes a lethal infectious prion dose.

Conclusion. CWD prions are shed in saliva and urine of infected deer as
early as 3 months post infection and throughout the subsequent >1.5 year
course of infection. In current work we are examining the relationship of
prionemia to excretion and the impact of excreted prion binding to surfaces and
particulates in the environment.

Background/Introduction. Chronic wasting disease (CWD) is unique among
prion diseases in its efficient lateral transmission in nature, yet the dynamics
and magnitude of shedding and its immediate and long term consequences remain
unknown. The present study was designed to determine the frequency and time span
in which CWD prions are shed in urine from infected white-tailed deer using
adapted real-time quaking-induced conversion (RT-QuIC) methodology.

Materials and Methods. Longitudinal urine samples were collected by free
catch or catheterization over a 2-year period from oral-route infected [CWD+ (n
= 11)] and aerosol-route-infected [CWD+ (n = 6); CWD- (n = 3)] white-tailed
deer. High speed centrifugation pelleted material from 500 µl of urine was
treated with sodium phosphotungstic acid (Na-PTA), resuspended in 0.05% SDS
buffer, and used as seed in RT-QuIC assays employing recombinant Syrian hamster
prion PrP substrate. Eight (8) replicates of each sample were run and prion
seeding activity was recorded as thioflavin T binding fluorescence (480 nm
emission) using a fluorimeter-shaker. Samples were considered positive if they
crossed an established threshold (5 standard deviations above the negative mean
fluorescence).

Results. In our oral-route inoculation studies, prion seeding activity has
been demonstrated in urine collected at 6 months post-inoculation in 6 of 10
deer (11 of 80 replicates; 14%), and intermittently at later time points in all
11 CWD+ exposed deer. Our aerosol-route inoculation studies also showed prion
seeding activity in urine collected at 6 months post-inoculation in 1 of 2 deer
(3 of 16 replicates; 19%), and intermittently at later time points in 4 of 6
CWD+ exposed deer. Urine from sham-inoculated control deer and all baseline
samples yielded 3 false-positive prion seeding activities (3 of 352 replicates;
0.8%).

Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC)
are shed in urine of infected deer as early as 6 months post inoculation and
throughout the subsequent disease course. Further studies are in progress
refining the real-time urinary prion assay sensitivity and we are examining more
closely the excretion time frame, magnitude, and sample variables in
relationship to inoculation route and prionemia in naturally and experimentally
CWD-infected cervids.

Prions can exist as multiple strains within mammals. We could detect, for
the first time, two distinct chronic wasting disease (CWD) isolates in
white-tailed deer (WTD).

WTD had been challenged with CWD from either mule deer (MD) or WTD.
Brain-derived prions from MD-infected WTD and WTD-infected WTD could be
distinguished by biochemical, biophysical and biological methods. PK-mediated
limited proteolysis at different pH-values indicated conformational differences
between pathological prion proteins (PrPTSE) from MD-infected WTD and
WTD-infected WTD. More specifically, Fouriertransform infrared microspectroscopy
revealed secondary structure differences between highly purified PrPTSE extracts
from MD-infected WTD and WTD-infected WTD. Different sedimentation velocities of
PrPTSE in gradient centrifugations provided additional evidence for structure
differences between prions from MD-infected WTD and WTD-infected WTD. Brain
homogenate from WTD-infected WTD showed a substantially lower seeding activity
on cellular prion protein (PrPC) of Syrian hamsters in protein misfolding cyclic
amplification (PMCA) than its conformationally distinct counterpart from
MD-infected WTD. When hamsters were intracerebrally inoculated with brain tissue
from MD-infected WTD disease could be transmitted, which was not observed after
similar inoculation with brain homogenate from WTD-infected WTD. In an ongoing
macaque-study both CWD-isolates are currently being further tested for their
transmissibility to primates.

P.163: Bayesian hierarchical modeling of chronic wasting disease in
free-ranging white-tailed deer in the eastern U.S.

Tyler S Evans1 and W David Walter2 1Pennsylvania Cooperative Fish and
Wildlife Research Unit; The Pennsylvania State University; University Park, PA
USA; 2US Geological Survey; Pennsylvania Cooperative Fish and Wildlife Research
Unit; The Pennsylvania State University; University Park, PA USA

Introduction. Chronic wasting disease (CWD) is a prion disease that affects
both free-ranging and captive cervid populations. In the past 45 years, CWD has
spread from a single region in Colorado to all bordering states, as well as
Canada, the Midwest and the northeastern United States. In 2005, CWD was
detected in the eastern U.S. in a free-ranging white-tailed deer (Odocoileus
virginianus) killed by a vehicle in West Virginia followed by positives from
Virginia, Maryland, and Pennsylvania. Although considerable information has been
learned about CWD in wildlife from several areas of the U.S. and Canada, little
information is available on spatial epidemiology of disease in the eastern
U.S.

Materials and Methods. In order to develop a CWD surveillance plan for the
region, we determined covariates and the best scale for analysis by exploring
habitat use and estimating the mean size of home range for deer in the central
Appalachian region (6 km2). We conducted Bayesian hierarchical modeling in
WinBUGS on 24 a priori models using 11,320 free-ranging white-tailed deer (69
positive, 11,251 negative) that have been tested for CWD since 2005. Testing for
CWD was conducted using standard protocols on a variety of tissues extracted
from hunter-harvested deer that included retropharyngeal lymph nodes, tonsil
lymph nodes, and the medulla oblongata sectioned at the obex.

Results. We found 94% of models weights were accounted for in our top model
that identified habitats such as developed and open as covariates that increased
the odds of infection for CWD in this region. Contrary to research in the
endemic area of Colorado, we did not identify clay soil as a significant
predictor of disease even though clay soil ranged from 9% to 19% in our study
samples. Furthermore, contrary to results from the recent expansion of CWD into
the agricultural Midwestern U.S. (Wisconsin, Illinois), we identified developed
and open habitats were better predictors of disease occurrence compared to
forest habitat considered more critical to deer population dynamics in the
U.S.

Conclusions. Our results suggested that the odds of infection for CWD is
likely controlled by areas that congregate deer thus increasing direct
transmission (deer-to-deer interactions) or indirect transmission
(deer-to-environment) by sharing or depositing infectious prion proteins in
these preferred habitats. Epidemiology of CWD in the eastern U.S. is likely
controlled by separate factors than found in the Midwestern and endemic areas
for CWD and can assist in performing more efficient surveillance efforts for the
region.

Background/Introduction. Chronic Wasting Disease (CWD) is an emergent
rapidly spreading fatal prion disease of cervids (deer, elk and moose). CWD has
now been identified in 22 States (including two new states within the last
year), 2 Canadian provinces, and South Korea. Shedding of infectious prions in
excreta (saliva, urine, feces) may be an important factor in CWD transmission.
Here we apply an adapted version of a rapid in vitro assay [real-time
quaking-induced conversion (RT-QuIC)] to determine the time of onset, length,
pattern, and magnitude of prion shedding in saliva of infected deer.

Materials and Methods. The RT-QuIC assay was performed as previously
described in Henderson et al. PLoS-One (2013). Saliva samples were quantitated
by comparison to a RT-QuIC reaction rate standard curve of a bioassayed obex
sample from a terminally ill cervid.

Results. To better understand the onset and length of CWD prion shedding we
analyzed >150 longitudinally collected, blinded, then randomized saliva
samples from 17 CWD-infected and 3 uninfected white-tailed deer. We observed
prion shedding, as detected by the RT-QuIC assay, as early as 3 months from
inoculation and sustained shedding throughout the disease course in both aerosol
and orally exposed deer. We estimated the infectious lethal dose of prions shed
in saliva from infected deer by comparing real-time reaction rates of saliva
samples to a bioassayed serially diluted brain control. Our results indicate
that as little as 1 ml of saliva from pre-symptomatic infected deer constitutes
a lethal CWD prion dose.

Conclusions. During the pre-symptomatic stage of CWD infection and
throughout the course of disease deer may be shedding multiple LD50 doses per
day in their saliva. CWD prion shedding through saliva and excreta may account
for the unprecedented spread of this prion disease in nature.

The alkaline hydrolysis process has been through a validation study by the
Institute of Animal Health, and an Opinion has been issued by the Scientific
Steering Committee of the European Commission (EC 2002) on the effectiveness of
the process. There was detectable infectivity from samples held for 3 hours, but
not from samples held for 6 hours. The committee concluded that the by-products
after 3 hours of processing could contain some residual TSE infectivity and that
this risk may decrease with increased duration of processing.

There are many disposal options for dead livestock currently in use
throughout the world; however, the knowledge that TSEs and some pathogens may
not be completely destroyed may limit their utility in the wake of changing
legislation (e.g. the amended EU Animal By-Products Regulation (1069/2009) which
comes into effect in March 2011). On-farm disposal methods are favoured by the
farming community due to the perceived environmental, practical, economical and
biosecurity benefits, therefore processes such as composting and anaerobic
digestion have found favour in countries such as the USA and Canada. Under the
ABPR in the EU, these options are not deemed safe;

========================================

Review

The environmental and biosecurity characteristics of livestock carcass
disposal methods: A review

Livestock mortalities represent a major waste stream within agriculture.
Many different methods are used throughout the world to dispose of these
mortalities; however within the European Union (EU) disposal options are limited
by stringent legislation. The legal disposal options currently available to EU
farmers (primarily rendering and incineration) are frequently negatively
perceived on both practical and economic grounds. In this review, we assess the
potential environment impacts and biosecurity risks associated with each of the
main options used for disposal of livestock mortalities in the world and
critically evaluate the justification for current EU regulations. Overall, we
conclude that while current legislation intends to minimise the potential for
on-farm pollution and the spread of infectious diseases (e.g. transmissible
spongiform encephalopathies, bacterial pathogens), alternative technologies
(e.g. bioreduction, anaerobic digestion) may provide a more cost-effective,
practical and biosecure mechanism for carcass disposal as well as having a lower
environmental footprint. Further social, environmental and economic research is
therefore warranted to assess the holistic benefits of alternative approaches
for carcass disposal in Europe, with an aim to provide policy-makers with robust
knowledge to make informed decisions on future legislation.

snip...

4. Conclusions

There are many disposal options for dead livestock currently in use
throughout the world; however, the knowledge that TSEs and some pathogens may
not be completely destroyed may limit their utility in the wake of changing
legislation (e.g. the amended EU Animal By-Products Regulation (1069/2009) which
comes into effect in March 2011). On-farm disposal methods are favoured by the
farming community due to the perceived environmental, practical, economical and
biosecurity benefits, therefore processes such as composting and anaerobic
digestion have found favour in countries such as the USA and Canada. Under the
ABPR in the EU, these options are not deemed safe; however, the legal
alternatives are not favoured by the farming community leading to widespread
non-compliance and potentially greater environmental risk (due to illegal
dumping, etc. (Kirby et al., 2010)). There is therefore a real need for new
methods to be developed and validated and the legislation reconsidered following
submission of new evidence. From this perspective, bioreduction and freezing
seems to be promising on-farm storage methods for livestock mortalities,
limiting the need for off farm transport thus reducing associated biosecurity
risks. While the implementation of highly precautionary, risk-averse mortality
disposal systems is admirable in many ways, similar risk assessments and
legislation do not apply to other components of the livestock sector which may
pose a similar or even greater risk to human health or environmental
contamination (e.g. spreading of animal waste, animal access to watercourses,
public access to grazing land). It is important therefore that mortality
disposal systems are based on a realistic and proportionate level of acceptable
risk in comparison to other components of the food chain, rather than the
current zero-risk approach. It is clear that more evidence is needed on each
disposal and storage method in order to make substantiated risk assessments,
e.g. the effects of spreading carcass ash on crops or the potential of leachate
from burial to contaminate ground or surface water. This review has initiated
this process by applying a simple five-star award system to each livestock
disposal and storage method (Table 3 and Table 4, respectively) in order to
rudimentarily classify various biosecurity and environmental factors based on
current scientific evidence. Methods in need of greater research have also been
highlighted where there is either limited or no existing published literature.
Further research into the economic impacts of dead livestock disposal is
necessary for legislators to appreciate the cost implications on the livestock
sector, whilst life-cycle assessments are needed to help provide more
environmentally sustainable disposal solutions.

Dr A Colchester BA BM BCh PhD FRCP Reader in Neurosciences & Computing,
University of Kent at Canterbury; Consultant Neurologist, Guy’s Hospital London
and William Harvey Hospital Ashford April 1999

snip...

88. Natural decay: Infectivity persists for a long time in the environment.
A study by Palsson in 1979 showed how scrapie was contracted by healthy sheep,
after they had grazed on land which had previously been grazed by
scrapie-infected sheep, even though the land had lain fallow for three years
before the healthy sheep were introduced. Brown also quoted an early experiment
of his own (1991), where he had buried scrapie-infected hamster brain and found
that he could still detect substantial infectivity three years later near where
the material had been placed. 89. Potential environmental routes of infection:
Brown discusses the various possible scenarios, including surface or subsurface
deposits of TSE-contaminated material, which would lead to a build-up of
long-lasting infectivity. Birds feeding on animal remains (such as gulls
visiting landfill sites) could disperse infectivity. Other animals could become
vectors if they later grazed on contaminated land. "A further question concerns
the risk of contamination of the surrounding water table or even surface water
channels, by effluents and discarded solid wastes from treatment plants. A
reasonable conclusion is that there is a potential for human infection to result
from environmental contamination by BSE-infected tissue residues. The potential
cannot be quantified because of the huge numbers of uncertainties and
assumptions that attend each stage of the disposal process". These comments,
from a long established authority on TSEs, closely echo my own statements which
were based on a recent examination of all the evidence. 90. Susceptibility: It
is likely that transmissibility of the disease to humans in vivo is probably
low, because sheep that die from scrapie and cattle that die from BSE are
probably a small fraction of the exposed population. However, no definitive data
are available.

91. Recommendations for disposal procedures: Brown recommends that material
which is actually or potentially contaminated by BSE should be: 1) exposed to
caustic soda; 2) thoroughly incinerated under carefully inspected conditions;
and 3) that any residue should be buried in landfill, to a depth which would
minimise any subsequent animal or human exposure, in areas that would not
intersect with any potable water-table source.

92. This review and recommendations from Brown have particular importance.
Brown is one of the world's foremost authorities on TSEs and is a senior
researcher in the US National Institutes of Health (NIH). It is notable that
such a respected authority is forthright in acknowledging the existence of
potential risks, and in identifying the appropriate measures necessary to
safeguard public health. Paper by SM Cousens, L Linsell, PG Smith, Dr M
Chandrakumar, JW Wilesmith, RSG Knight, M Zeidler, G Stewart, RG Will,
"Geographical distribution of variant CJD in the UK (excluding Northern
Ireland)". Lancet 353:18-21, 2 nd January 1999 93. The above paper {Appendix 41
(02/01/99)} (J/L/353/18) examined the possibility that patients with vCJD
(variant CJD) might live closer to rendering factories than would be expected by
chance. All 26 cases of vCJD in the UK with onset up to 31 st August 1998 were
studied. The incubation period of vCJD is not known but by analogy with other
human TSEs could lie within the range 5-25 years. If vCJD had arisen by exposure
to rendering products, such exposure might plausibly have occurred 8-10 years
before the onset of symptoms. The authors were able to obtain the addresses of
all rendering plants in the UK which were in production in 1988. For each case
of vCJD, the distance from the place of residence on 1st January 1998 to the
nearest rendering plant was calculated

As early as 1992-3 there had been long studies conducted on small pastures
containing scrapie infected sheep at the sheep research station associated with
the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are
documented...I don't know. But personal recounts both heard and recorded in a
daily journal indicate that leaving the pastures free and replacing the topsoil
completely at least 2 feet of thickness each year for SEVEN years....and then
when very clean (proven scrapie free) sheep were placed on these small
pastures.... the new sheep also broke with scrapie and passed it to offspring. I
am not sure that TSE contaminated ground could ever be free of the agent!! A
very frightening revelation!!!

xxxxxxxxxxx

you can take that with however many grains of salt you wish, and we can
debate these issues all day long, but bottom line, this is not rocket-science,
all one has to do is some experiments and case studies, but for the life of me,
i don't know what they are waiting on?

well heck, this is just typical public relations fear factor control. do
you actually think they would spend the extra costs for fuel, for such extreme
heat, just to eliminate smell, when they spread manure all over your veg's. i
think not. what they really meant were any _TSE agents_.

b. Gas scrubbing to eliminate smoke -- though steam may be omitted;

c. Stacks to be fitted with grit arreaters;

snip...

1.2 Visual Imact

It is considered that the requirement for any carcase incinerator disign
would be to ensure that the operations relating to the reception, storage and
decepitation of diseased carcasses must not be publicly visible and that any
part of a carcase could not be removed or interfered with by animals or birds.

Between 1996 and 2002, chronic wasting disease was diagnosed in 39 herds of
farmed elk in Saskatchewan in a single epidemic. All of these herds were
depopulated as part of the Canadian Food Inspection Agency’s (CFIA) disease
eradication program. Animals, primarily over 12 mo of age, were tested for the
presence CWD prions following euthanasia. Twenty-one of the herds were linked
through movements of live animals with latent CWD from a single infected source
herd in Saskatchewan, 17 through movements of animals from 7 of the secondarily
infected herds.

***The source herd is believed to have become infected via importation of
animals from a game farm in South Dakota where CWD was subsequently diagnosed
(7,4). A wide range in herd prevalence of CWD at the time of herd depopulation
of these herds was observed. Within-herd transmission was observed on some
farms, while the disease remained confined to the introduced animals on other
farms.

Chronic wasting disease (CWD) has been recognized as an important prion
disease in native North America deer and Rocky mountain elks. The disease is a
unique member of the transmissible spongiform encephalopathies (TSEs), which
naturally affects only a few species. CWD had been limited to USA and Canada
until 2000.

On 28 December 2000, information from the Canadian government showed that a
total of 95 elk had been exported from farms with CWD to Korea. These consisted
of 23 elk in 1994 originating from the so-called “source farm” in Canada, and 72
elk in 1997, which had been held in pre export quarantine at the “source
farm”.Based on export information of CWD suspected elk from Canada to Korea, CWD
surveillance program was initiated by the Ministry of Agriculture and Forestry
(MAF) in 2001.

All elks imported in 1997 were traced back, however elks imported in 1994
were impossible to identify. CWD control measures included stamping out of all
animals in the affected farm, and thorough cleaning and disinfection of the
premises. In addition, nationwide clinical surveillance of Korean native
cervids, and improved measures to ensure reporting of CWD suspect cases were
implemented.

Total of 9 elks were found to be affected. CWD was designated as a
notifiable disease under the Act for Prevention of Livestock Epidemics in 2002.

Since February of 2005, when slaughtered elks were found to be positive,
all slaughtered cervid for human consumption at abattoirs were designated as
target of the CWD surveillance program. Currently, CWD laboratory testing is
only conducted by National Reference Laboratory on CWD, which is the Foreign
Animal Disease Division (FADD) of National Veterinary Research and Quarantine
Service (NVRQS).

In July 2010, one out of 3 elks from Farm 1 which were slaughtered for the
human consumption was confirmed as positive. Consequently, all cervid – 54 elks,
41 Sika deer and 5 Albino deer – were culled and one elk was found to be
positive. Epidemiological investigations were conducted by Veterinary
Epidemiology Division (VED) of NVRQS in collaboration with provincial veterinary
services.

Epidemiologically related farms were found as 3 farms and all cervid at
these farms were culled and subjected to CWD diagnosis. Three elks and 5
crossbreeds (Red deer and Sika deer) were confirmed as positive at farm 2.

All cervids at Farm 3 and Farm 4 – 15 elks and 47 elks – were culled and
confirmed as negative.

Further epidemiological investigations showed that these CWD outbreaks were
linked to the importation of elks from Canada in 1994 based on circumstantial
evidences.

In December 2010, one elk was confirmed as positive at Farm 5.
Consequently, all cervid – 3 elks, 11 Manchurian Sika deer and 20 Sika deer –
were culled and one Manchurian Sika deer and seven Sika deer were found to be
positive. This is the first report of CWD in these sub-species of deer.
Epidemiological investigations found that the owner of the Farm 2 in CWD
outbreaks in July 2010 had co-owned the Farm 5.

In addition, it was newly revealed that one positive elk was introduced
from Farm 6 of Jinju-si Gyeongsang Namdo. All cervid – 19 elks, 15 crossbreed
(species unknown) and 64 Sika deer – of Farm 6 were culled, but all confirmed as
negative.

how many states have $465,000., and can quarantine and purchase there from,
each cwd said infected farm, but how many states can afford this for all the cwd
infected cervid game ranch type farms, and this is just one cwd infected farm,
which had the highest documented infection rate of cwd, documented at 80%.

The CWD infection rate was nearly 80%, the highest ever in a North American
captive herd. RECOMMENDATION: That the Board approve the purchase of 80 acres of
land for $465,000 for the Statewide Wildlife Habitat Program in Portage County
and approve the restrictions on public use of the site.

There were 26 reported escape incidents so far this year, this amounted to
20 actual confirmed escape incidents because 3 were previously reported, 2 were
confirmed as wild deer, and 1 incident was not confirmed. ...

There were 26 reported escape incidents so far this year, this amounted to
20 actual confirmed escape incidents because 3 were previously reported, 2 were
confirmed as wild deer, and 1 incident was not confirmed. Approximately 30% of
these escapes were caused by gates being left open and the other 70% resulted
from bad fencing or fence related issues. The 20 actual confirmed escape
incidents amounted to 77 total animals. 50 of the escaped animals were recovered
or killed and 27 were not recovered and remain unaccounted for. Last year the
CWD Committee passed a resolution to require double gates, but this has not gone
into effect yet. Questions were raised by the committee about double fencing
requirements? Pete responded that double fencing has not been practical or
accepted by the industry. The DNR has the authority to do fence inspections. ?
If a fence fails to pass the inspection the fencing certificate can be revoked
and the farmer can be issued a citation. This year three citations and one
warning have been issued for escapes. Pete reviewed the reporting requirements
for escape incidents that these must be reported within 24 hours. The farmer
then has 72 hours to recover the animals or else it will affect the farm’s herd
status and ability to move animals. Davin proposed in the 15 year CWD Plan that
the DNR take total control and regulatory authority over all deer farm fencing.
Larry Gohlke asked Pete about the reliability for reporting escapes? Pete said
that the majority of escapes were reported by the farmer, but it is very
difficult to determine when an escape actually occurred. Pete said that they are
more concerned that an escape is reported and not that it is reported at the
exact time that it happened.

A state inspection of private deer farms, prompted by the discovery of
chronic wasting disease, found that 436 white-tailed deer escaped into the wild,
officials said Tuesday

The Department of Natural Resources found that captive deer have escaped
from one-third of the state's 550 deer farms over the lifetime of the
operations. The agency also uncovered hundreds of violations and has sought a
total of 60 citations or charges against deer farm operators.

snip...

CWD found on 2 farms

Seven deer have tested positive for the disease on game farms - one on a
Portage County farm and six on a Walworth County farm - since the disease was
discovered in three wild deer killed near Mount Horeb in western Dane County.
One deer that tested positive on the Walworth County farm escaped and roamed
free for six months.

snip...

The audit found that most farms were in compliance, but the DNR found many
violations and instances of poor record keeping. Also in numerous instances,
fences did not stop wild and captive deer from intermingling.

At least 227 farms conducted part of their business on a cash basis, making
it hard to track animal movement with financial records.

For example, both the Internal Revenue Service and the state Department of
Revenue have been contacted about a deer farm near Wild Rose in Waushara County
that is suspected of selling six large bucks for $45,000 in cash and not using
live deer shipping tags as required.

The DNR found that game farm operators have more deer in captivity than
their records show, which is "due in part because the owners of a number of
large deer farm operations were! unable to accurately count the number of deer
within their fences," the audit found.

Hundreds of deer escape

The DNR found a total of 671 deer that escaped farms - 436 of which were
never found - because of storm-damaged fences, gates being left open or the
animals jumping over or through fences.

In one example in Kewaunee County, a deer farmer's fence was knocked down
in a summer storm. Ten deer escaped, and the farmer told the DNR he had no
intention of trying to reclaim them. The DNR found five of the deer, killed them
and cited the farmer for violation of a regulation related to fencing.

Another deer farmer near Mishicot, in Manitowoc County, released all nine
of his whitetails last summer after he believed the discovery of chronic wasting
disease was going to drive down the market for captive deer.

The DNR found 24 instances of unlicensed deer farms and issued 19
citations.

A summary of the findings of the Department of Natural Resources'
inspection of 550 private white-tailed deer farms in the state: The deer farms
contained at least 16,070 deer, but the DNR believes there are more deer in
captivity than that because large deer farms are unable to accurately count
their deer. 671 deer had escaped from game farms, including 436 that were never
found.

24 farmers were unlicensed. One had been operating illegally since 1999
after he was denied a license because his deer fence did not meet minimum
specifications.

Records maintained by operators ranged from "meticulous documentation to
relying on memory." At least 227 farms conducted various portions of their deer
farm business with cash. Over the last three years, 1,222 deer died on farms for
various reasons. Disease testing was not performed nor required on the majority
of deer. Farmers reported doing business with people in 22 other states and one
Canadian province. Click these links for more information

The initial discovery at Wilderness Whitetails was the first in five years.
In trying to explain the sudden appearance, McGraw cited several possibilities
for transmission, including the chance it occurred spontaneously.

That drew attention of Clausen and wildlife staff at the DNR. Clausen said
he knew of no peer-reviewed research showing the disease turned up that way.

Tami Ryan, wildlife health section chief with the DNR, asked the
agriculture department to back up the claim.

Richard Bourie, a veterinarian, pointed to a paper by Nobel Laureate
Stanley Prusiner of the University of California, San Francisco, who discussed
spontaneous occurrence in TSEs.

*** Ryan wrote back and said, "to the best of our collective knowledge,
spontaneous CWD in wild deer has not been substantiated," although she said the
DNR wasn't trying to pick a fight.

Said McGraw: "There is no battle going on here. We all read science here.
Everybody looks at different possibilities."

Approximately 4,200 fawns, defined as deer under 1 year of age, were
sampled from the eradication zone over the last year. The majority of fawns
sampled were between the ages of 5 to 9 months, though some were as young as 1
month.

*** Two of the six fawns with CWD detected were 5 to 6 months old.

All six of the positive fawns were taken from the core area of the CWD
eradication zone where the highest numbers of positive deer have been
identified.

”The occurrence of CWD must be viewed against the contest of the locations
in which it occurred. It was an incidental and unwelcome complication of the
respective wildlife research programmes. Despite it’s subsequent recognition as
a new disease of cervids, therefore justifying direct investigation, no specific
research funding was forthcoming. The USDA veiwed it as a wildlife problem and
consequently not their province!” ...page 26.

*** The potential impact of prion diseases on human health was greatly
magnified by the recognition that interspecies transfer of BSE to humans by beef
ingestion resulted in vCJD. While changes in animal feed constituents and
slaughter practices appear to have curtailed vCJD, there is concern that CWD of
free-ranging deer and elk in the U.S. might also cross the species barrier.
Thus, consuming venison could be a source of human prion disease. Whether BSE
and CWD represent interspecies scrapie transfer or are newly arisen prion
diseases is unknown. Therefore, the possibility of transmission of prion disease
through other food animals cannot be ruled out. There is evidence that vCJD can
be transmitted through blood transfusion. There is likely a pool of unknown size
of asymptomatic individuals infected with vCJD, and there may be asymptomatic
individuals infected with the CWD equivalent.

*** These results would seem to suggest that CWD does indeed have zoonotic
potential, at least as judged by the compatibility of CWD prions and their human
PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests
that if zoonotic CWD occurred, it would most likely effect those of the PRNP
codon 129-MM genotype and that the PrPres type would be similar to that found in
the most common subtype of sCJD (MM1).

White-tailed Deer are Susceptible to Scrapie by Natural Route of Infection

Jodi D. Smith, Justin J. Greenlee, and Robert A. Kunkle; Virus and Prion
Research Unit, National Animal Disease Center, USDA-ARS Interspecies
transmission studies afford the opportunity to better understand the potential
host range and origins of prion diseases. Previous experiments demonstrated that
white-tailed deer are susceptible to sheep-derived scrapie by intracranial
inoculation. The purpose of this study was to determine susceptibility of
white-tailed deer to scrapie after a natural route of exposure. Deer (n=5) were
inoculated by concurrent oral (30 ml) and intranasal (1 ml) instillation of a
10% (wt/vol) brain homogenate derived from a sheep clinically affected with
scrapie. Non-inoculated deer were maintained as negative controls. All deer were
observed daily for clinical signs. Deer were euthanized and necropsied when
neurologic disease was evident, and tissues were examined for abnormal prion
protein (PrPSc) by immunohistochemistry (IHC) and western blot (WB). One animal
was euthanized 15 months post-inoculation (MPI) due to an injury. At that time,
examination of obex and lymphoid tissues by IHC was positive, but WB of obex and
colliculus were negative. Remaining deer developed clinical signs of wasting and
mental depression and were necropsied from 28 to 33 MPI. Tissues from these deer
were positive for scrapie by IHC and WB. Tissues with PrPSc immunoreactivity
included brain, tonsil, retropharyngeal and mesenteric lymph nodes, hemal node,
Peyer’s patches, and spleen. This work demonstrates for the first time that
white-tailed deer are susceptible to sheep scrapie by potential natural routes
of inoculation. In-depth analysis of tissues will be done to determine
similarities between scrapie in deer after intracranial and oral/intranasal
inoculation and chronic wasting disease resulting from similar routes of
inoculation.

We intracerebrally challenged four species of native North American rodents
that inhabit locations undergoing cervid chronic wasting disease (CWD)
epidemics. The species were: deer mice (Peromyscus maniculatus), white-footed
mice (P. leucopus), meadow voles (Microtus pennsylvanicus), and red-backed voles
(Myodes gapperi). The inocula were prepared from the brains of hunter-harvested
white-tailed deer from Wisconsin that tested positive for CWD. Meadow voles
proved to be most susceptible, with a median incubation period of 272 days.
Immunoblotting and immunohistochemistry confirmed the presence of PrPd in the
brains of all challenged meadow voles. Subsequent passages in meadow voles lead
to a significant reduction in incubation period. The disease progression in
red-backed voles, which are very closely related to the European bank vole (M.
glareolus) which have been demonstrated to be sensitive to a number of TSEs, was
slower than in meadow voles with a median incubation period of 351 days. We
sequenced the meadow vole and red-backed vole Prnp genes and found three amino
acid (AA) differences outside of the signal and GPI anchor sequences. Of these
differences (T56-, G90S, S170N; read-backed vole:meadow vole), S170N is
particularly intriguing due its postulated involvement in "rigid loop" structure
and CWD susceptibility. Deer mice did not exhibit disease signs until nearly 1.5
years post-inoculation, but appear to be exhibiting a high degree of disease
penetrance. White-footed mice have an even longer incubation period but are also
showing high penetrance. Second passage experiments show significant shortening
of incubation periods. Meadow voles in particular appear to be interesting lab
models for CWD. These rodents scavenge carrion, and are an important food source
for many predator species. Furthermore, these rodents enter human and domestic
livestock food chains by accidental inclusion in grain and forage. Further
investigation of these species as potential hosts, bridge species, and
reservoirs of CWD is required.

Thank you for your correspondence regarding the review article Stanley
Prusiner and I recently wrote for Cold Spring Harbor Perspectives. Dr. Prusiner
asked that I reply to your message due to his busy schedule. We agree that the
transmission of CWD prions to beef livestock would be a troubling development
and assessing that risk is important. In our article, we cite a peer-reviewed
publication reporting confirmed cases of laboratory transmission based on
stringent criteria. The less stringent criteria for transmission described in
the abstract you refer to lead to the discrepancy between your numbers and ours
and thus the interpretation of the transmission rate. We stand by our assessment
of the literature--namely that the transmission rate of CWD to bovines appears
relatively low, but we recognize that even a low transmission rate could have
important implications for public health and we thank you for bringing attention
to this matter. Warm Regards, David Colby -- David Colby, PhDAssistant Professor
Department of Chemical Engineering University of Delaware

*** The discovery of previously unrecognized prion diseases in both humans
and animals (i.e., Nor98 in small ruminants) demonstrates that the range of
prion diseases might be wider than expected and raises crucial questions about
the epidemiology and strain properties of these new forms. We are investigating
this latter issue by molecular and biological comparison of VPSPr, GSS and
Nor98.

VARIABLY PROTEASE-SENSITVE PRIONOPATHY IS TRANSMISSIBLE ...price of prion
poker goes up again $

Background. Variably protease-sensitive prionopathy (VPSPr) is a recently
described “sporadic”neurodegenerative disease involving prion protein
aggregation, which has clinical similarities with non-Alzheimer dementias, such
as fronto-temporal dementia. Currently, 30 cases of VPSPr have been reported in
Europe and USA, of which 19 cases were homozygous for valine at codon 129 of the
prion protein (VV), 8 were MV and 3 were MM. A distinctive feature of VPSPr is
the electrophoretic pattern of PrPSc after digestion with proteinase K (PK).
After PK-treatment, PrP from VPSPr forms a ladder-like electrophoretic pattern
similar to that described in GSS cases. The clinical and pathological features
of VPSPr raised the question of the correct classification of VPSPr among prion
diseases or other forms of neurodegenerative disorders. Here we report
preliminary data on the transmissibility and pathological features of VPSPr
cases in bank voles.

Materials and Methods. Seven VPSPr cases were inoculated in two genetic
lines of bank voles, carrying either methionine or isoleucine at codon 109 of
the prion protein (named BvM109 and BvI109, respectively). Among the VPSPr cases
selected, 2 were VV at PrP codon 129, 3 were MV and 2 were MM. Clinical
diagnosis in voles was confirmed by brain pathological assessment and western
blot for PK-resistant PrPSc (PrPres) with mAbs SAF32, SAF84, 12B2 and 9A2.

Results. To date, 2 VPSPr cases (1 MV and 1 MM) gave positive transmission
in BvM109. Overall, 3 voles were positive with survival time between 290 and 588
d post inoculation (d.p.i.). All positive voles accumulated PrPres in the form
of the typical PrP27–30, which was indistinguishable to that previously observed
in BvM109 inoculated with sCJDMM1 cases.

In BvI109, 3 VPSPr cases (2 VV and 1 MM) showed positive transmission until
now. Overall, 5 voles were positive with survival time between 281 and 596
d.p.i.. In contrast to what observed in BvM109, all BvI109 showed a GSS-like
PrPSc electrophoretic pattern, characterized by low molecular weight PrPres.
These PrPres fragments were positive with mAb 9A2 and 12B2, while being negative
with SAF32 and SAF84, suggesting that they are cleaved at both the C-terminus
and the N-terminus. Second passages are in progress from these first successful
transmissions.

Conclusions. Preliminary results from transmission studies in bank voles
strongly support the notion that VPSPr is a transmissible prion disease.
Interestingly, VPSPr undergoes divergent evolution in the two genetic lines of
voles, with sCJD-like features in BvM109 and GSS-like properties in BvI109.

The discovery of previously unrecognized prion diseases in both humans and
animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion
diseases might be wider than expected and raises crucial questions about the
epidemiology and strain properties of these new forms. We are investigating this
latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.

4 Disease was acquired in the United Kingdom in one case and in Saudi
Arabia in the other case;

5 Includes 14 cases in which the diagnosis is pending, and 18 inconclusive
cases;

6 Includes 17 (16 from 2012) cases with type determination pending in which
the diagnosis of vCJD has been excluded. The Sporadic cases include 16 cases of
sporadic Fatal Insomnia (sFI) and 42 cases of Variably Protease-Sensitive
Prionopathy (VPSPr) and 2118 cases of sporadic Creutzfeldt-Jakob disease (sCJD).

WELL, it seems the USA mad cow strains in humans classified as type
determination pending tdpCJD, VPSPr, sFFI, and sCJD) have steadily increased
over the years, and the same old song and dance continues with sporadic CJD
cases $$$

*** The discovery of previously unrecognized prion diseases in both humans
and animals (i.e., Nor98 in small ruminants) demonstrates that the range of
prion diseases might be wider than expected and raises crucial questions about
the epidemiology and strain properties of these new forms. We are investigating
this latter issue by molecular and biological comparison of VPSPr, GSS and
Nor98.

Increased Atypical Scrapie Detections

Press reports indicate that increased surveillance is catching what
otherwise would have been unreported findings of atypical scrapie in sheep. In
2009, five new cases have been reported in Quebec, Ontario, Alberta, and
Saskatchewan. With the exception of Quebec, all cases have been diagnosed as
being the atypical form found in older animals. Canada encourages producers to
join its voluntary surveillance program in order to gain scrapie-free status.
The World Animal Health will not classify Canada as scrapie-free until no new
cases are reported for seven years. The Canadian Sheep Federation is calling on
the government to fund a wider surveillance program in order to establish the
level of prevalence prior to setting an eradication date. Besides long-term
testing, industry is calling for a compensation program for farmers who report
unusual deaths in their flocks.

Volume 17, Number 5-May 2011 However, work with transgenic mice has
demonstrated the potential susceptibility of pigs, with the disturbing finding
that the biochemical properties of the resulting PrPSc have changed on
transmission (40).

The detection of bovine spongiform encephalopathy (BSE) has had a
significant negative impact on the cattle industry worldwide. In response,
governments took actions to prevent transmission and additional threats to
animal health and food safety. While these measures seem to be effective for
controlling classical BSE, the more recently discovered atypical BSE has
presented a new challenge. To generate data for risk assessment and control
measures, we have challenged cattle orally with atypical BSE to determine
transmissibility and mis-folded prion (PrPSc) tissue distribution. Upon
presentation of clinical symptoms, animals were euthanized and tested for
characteristic histopathological changes as well as PrPSc deposition.

The H-type challenged animal displayed vacuolation exclusively in rostral
brain areas but the L-type challenged animal showed no evidence thereof. To our
surprise, neither of the animals euthanized, which were displaying clinical
signs indicative of BSE, showed conclusive mis-folded prion accumulation in the
brain or gut using standard molecular or immunohistochemical assays. To confirm
presence or absence of prion infectivity, we employed an optimized real-time
quaking induced conversion (RT-QuIC) assay developed at the Rocky Mountain
Laboratory, Hamilton, USA.

Detection of PrPSc was unsuccessful for brain samples tests from the orally
inoculated L type animal using the RT-QuIC. It is possible that these negative
results were related to the tissue sampling locations or that type specific
optimization is needed to detect PrPSc in this animal. We were however able to
consistently detect the presence of mis-folded prions in the brain of the H-type
inoculated animal. Considering the negative and inconclusive results with other
PrPSc detection methods, positive results using the optimized RT-QuIC suggests
the method is extremely sensitive for H-type BSE detection. This may be evidence
of the first successful oral transmission of H type atypical BSE in cattle and
additional investigation of samples from these animals are ongoing.

Norway Nor98 is a prion disease of old sheep and goats. This atypical form
of scrapie was first described in Norway in 1998. Several features of Nor98 were
shown to be different from classical scrapie including the distribution of
disease associated prion protein (PrPd) accumulation in the brain. The
cerebellum is generally the most affected brain area in Nor98. The study here
presented aimed at adding information on the neuropathology in the cerebellum of
Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A
panel of histochemical and immunohistochemical (IHC) stainings such as IHC for
PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers
for phagocytic cells were conducted. The type of histological lesions and tissue
reactions were evaluated. The types of PrPd deposition were characterized. The
cerebellar cortex was regularly affected, even though there was a variation in
the severity of the lesions from case to case. Neuropil vacuolation was more
marked in the molecular layer, but affected also the granular cell layer. There
was a loss of granule cells. Punctate deposition of PrPd was characteristic. It
was morphologically and in distribution identical with that of synaptophysin,
suggesting that PrPd accumulates in the synaptic structures. PrPd was also
observed in the granule cell layer and in the white matter. The pathology
features of Nor98 in the cerebellum of the affected sheep showed similarities
with those of sporadic Creutzfeldt-Jakob disease in humans.

***The pathology features of Nor98 in the cerebellum of the affected sheep
showed similarities with those of sporadic Creutzfeldt-Jakob disease in
humans.

Molecular variants of PrPSc are being increasingly investigated in sheep
scrapie and are generally referred to as "atypical" scrapie, as opposed to
"classical scrapie". Among the atypical group, Nor98 seems to be the best
identified. We studied the molecular properties of Italian and Norwegian Nor98
samples by WB analysis of brain homogenates, either untreated, digested with
different concentrations of proteinase K, or subjected to enzymatic
deglycosylation. The identity of PrP fragments was inferred by means of
antibodies spanning the full PrP sequence. We found that undigested brain
homogenates contain a Nor98-specific PrP fragment migrating at 11 kDa (PrP11),
truncated at both the C-terminus and the N-terminus, and not N-glycosylated.
After mild PK digestion, Nor98 displayed full-length PrP (FL-PrP) and
N-glycosylated C-terminal fragments (CTF), along with increased levels of PrP11.
Proteinase K digestion curves (0,006-6,4 mg/ml) showed that FL-PrP and CTF are
mainly digested above 0,01 mg/ml, while PrP11 is not entirely digested even at
the highest concentrations, similarly to PrP27-30 associated with classical
scrapie. Above 0,2 mg/ml PK, most Nor98 samples showed only PrP11 and a fragment
of 17 kDa with the same properties of PrP11, that was tentatively identified as
a dimer of PrP11. Detergent solubility studies showed that PrP11 is insoluble in
2% sodium laurylsorcosine and is mainly produced from detergentsoluble,
full-length PrPSc. Furthermore, among Italian scrapie isolates, we found that a
sample with molecular and pathological properties consistent with Nor98 showed
plaque-like deposits of PrPSc in the thalamus when the brain was analysed by
PrPSc immunohistochemistry. Taken together, our results show that the
distinctive pathological feature of Nor98 is a PrP fragment spanning amino acids
~ 90-155. This fragment is produced by successive N-terminal and C-terminal
cleavages from a full-length and largely detergent-soluble PrPSc, is produced in
vivo and is extremely resistant to PK digestion.

*** Intriguingly, these conclusions suggest that some pathological features
of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.

***Edited by Stanley B. Prusiner, University of California, San Francisco,
CA (received for review March 21, 2005)

Abstract Scrapie in small ruminants belongs to transmissible spongiform
encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative
disorders that affect humans and animals and can transmit within and between
species by ingestion or inoculation. Conversion of the host-encoded prion
protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP
(PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified
surveillance of scrapie in the European Union, together with the improvement of
PrPSc detection techniques, has led to the discovery of a growing number of
so-called atypical scrapie cases. These include clinical Nor98 cases first
identified in Norwegian sheep on the basis of unusual pathological and PrPSc
molecular features and "cases" that produced discordant responses in the rapid
tests currently applied to the large-scale random screening of slaughtered or
fallen animals. Worryingly, a substantial proportion of such cases involved
sheep with PrP genotypes known until now to confer natural resistance to
conventional scrapie. Here we report that both Nor98 and discordant cases,
including three sheep homozygous for the resistant PrPARR allele (A136R154R171),
efficiently transmitted the disease to transgenic mice expressing ovine PrP, and
that they shared unique biological and biochemical features upon propagation in
mice.

*** These observations support the view that a truly infectious TSE agent,
unrecognized until recently, infects sheep and goat flocks and may have
important implications in terms of scrapie control and public health.

Atypical scrapie is a TSE occurring in small ruminants and harbouring
peculiar clinical, epidemiological and biochemical properties. Currently this
form of disease is identified in a large number of countries. In this study we
report the transmission of an atypical scrapie isolate through different species
barriers as modeled by transgenic mice (Tg) expressing different species PRP
sequence.

The donor isolate was collected in 1995 in a French commercial sheep flock.
inoculation into AHQ/AHQ sheep induced a disease which had all
neuro-pathological and biochemical characteristics of atypical scrapie.
Transmitted into Transgenic mice expressing either ovine or PrPc, the isolate
retained all the described characteristics of atypical scrapie.

Surprisingly the TSE agent characteristics were dramatically different
v/hen passaged into Tg bovine mice. The recovered TSE agent had biological and
biochemical characteristics similar to those of atypical BSE L in the same mouse
model. Moreover, whereas no other TSE agent than BSE were shown to transmit into
Tg porcine mice, atypical scrapie was able to develop into this model, albeit
with low attack rate on first passage.

Furthermore, after adaptation in the porcine mouse model this prion showed
similar biological and biochemical characteristics than BSE adapted to this
porcine mouse model. Altogether these data indicate.

(i) the unsuspected potential abilities of atypical scrapie to cross
species barriers

(ii) the possible capacity of this agent to acquire new characteristics
when crossing species barrier

These findings raise some interrogation on the concept of TSE strain and on
the origin of the diversity of the TSE agents and could have consequences on
field TSE control measures.

Press reports indicate that increased surveillance is catching what
otherwise would have been unreported findings of atypical scrapie in sheep. In
2009, five new cases have been reported in Quebec, Ontario, Alberta, and
Saskatchewan. With the exception of Quebec, all cases have been diagnosed as
being the atypical form found in older animals. Canada encourages producers to
join its voluntary surveillance program in order to gain scrapie-free status.
The World Animal Health will not classify Canada as scrapie-free until no new
cases are reported for seven years. The Canadian Sheep Federation is calling on
the government to fund a wider surveillance program in order to establish the
level of prevalence prior to setting an eradication date. Besides long-term
testing, industry is calling for a compensation program for farmers who report
unusual deaths in their flocks.

5. A positive result from a chimpanzee challenged severly would likely
create alarm in some circles even if the result could not be interpreted for
man. I have a view that all these agents could be transmitted provided a large
enough dose by appropriate routes was given and the animals kept long enough.
Until the mechanisms of the species barrier are more clearly understood it might
be best to retain that hypothesis.

Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep
and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were
exposed to the infectious agents only by their nonforced consumption of known
infectious tissues. The asymptomatic incubation period in the one monkey exposed
to the virus of kuru was 36 months; that in the two monkeys exposed to the virus
of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the
two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively.
Careful physical examination of the buccal cavities of all of the monkeys failed
to reveal signs or oral lesions. One additional monkey similarly exposed to kuru
has remained asymptomatic during the 39 months that it has been under
observation.

snip...

The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie
by natural feeding to squirrel monkeys that we have reported provides further
grounds for concern that scrapie-infected meat may occasionally give rise in
humans to Creutzfeldt-Jakob disease.

Recently the question has again been brought up as to whether scrapie is
transmissible to man. This has followed reports that the disease has been
transmitted to primates. One particularly lurid speculation (Gajdusek 1977)
conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and
transmissible encephalopathy of mink are varieties of a single "virus". The U.S.
Department of Agriculture concluded that it could "no longer justify or permit
scrapie-blood line and scrapie-exposed sheep and goats to be processed for human
or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is
emphasised by the finding that some strains of scrapie produce lesions identical
to the once which characterise the human dementias"

Whether true or not. the hypothesis that these agents might be
transmissible to man raises two considerations. First, the safety of laboratory
personnel requires prompt attention. Second, action such as the "scorched meat"
policy of USDA makes the solution of the acrapie problem urgent if the sheep
industry is not to suffer grievously.

Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).

Gibbs CJ Jr, Gajdusek DC.

Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0

Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)

C. J. GIBBS jun. & D. C. GAJDUSEK

National Institute of Neurological Diseases and Stroke, National Institutes
of Health, Bethesda, Maryland

SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey
(Macaca fascicularis) with an incubation period of more than 5 yr from the time
of intracerebral inoculation of scrapie-infected mouse brain. The animal
developed a chronic central nervous system degeneration, with ataxia, tremor and
myoclonus with associated severe scrapie-like pathology of intensive astroglial
hypertrophy and proliferation, neuronal vacuolation and status spongiosus of
grey matter. The strain of scrapie virus used was the eighth passage in Swiss
mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral
passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton,
Berkshire).

To investigate the possibility of oral transmission of atypical scrapie in
sheep and determine the distribution of infectivity in the animals’ peripheral
tissues, we challenged neonatal lambs orally with atypical scrapie; they were
then killed at 12 or 24 months. Screening test results were negative for
disease-specific prion protein in all but 2 recipients; they had positive
results for examination of brain, but negative for peripheral tissues.
Infectivity of brain, distal ileum, and spleen from all animals was assessed in
mouse bioassays; positive results were obtained from tissues that had negative
results on screening. These findings demonstrate that atypical scrapie can be
transmitted orally and indicate that it has the potential for natural
transmission and iatrogenic spread through animal feed. Detection of infectivity
in tissues negative by current surveillance methods indicates that diagnostic
sensitivity is suboptimal for atypical scrapie, and potentially infectious
material may be able to pass into the human food chain.

SNIP...

Although we do not have epidemiologic evidence that supports the effi cient
spread of disease in the fi eld, these data imply that disease is potentially
transmissible under fi eld situations and that spread through animal feed may be
possible if the current feed restrictions were to be relaxed. Additionally,
almost no data are available on the potential for atypical scrapie to transmit
to other food animal species, certainly by the oral route. However, work with
transgenic mice has demonstrated the potential susceptibility of pigs, with the
disturbing fi nding that the biochemical properties of the resulting PrPSc have
changed on transmission (40). The implications of this observation for
subsequent transmission and host target range are currently unknown.

How reassuring is this absence of detectable PrPSc from a public health
perspective? The bioassays performed in this study are not titrations, so the
infectious load of the positive gut tissues cannot be quantified, although
infectivity has been shown unequivocally. No experimental data are currently
available on the zoonotic potential of atypical scrapie, either through
experimental challenge of humanized mice or any meaningful epidemiologic
correlation with human forms of TSE. However, the detection of infectivity in
the distal ileum of animals as young as 12 months, in which all the tissues
tested were negative for PrPSc by the currently available screening and
confirmatory diagnostic tests, indicates that the diagnostic sensitivity of
current surveillance methods is suboptimal for detecting atypical scrapie and
that potentially infectious material may be able to pass into the human food
chain undetected.